Leyna Stemle

University of Miami
Teaching Assistant

Biography

I study reptile and amphibian habitat use and movement!

Education

Phd Biology
University of Miami
BS Marine Biology
Florida Southern College

Educator Statistics

Numerade tutor for 4 years
240 Students Helped

Topics Covered

Discover the Power of the Cell: Unleash Your Potential with Our Products
The Importance of Understanding the Cell Cycle for Cellular Reproduction
Discover the Fascinating World of Vertebrates: A Comprehensive Guide
Unlocking the Secrets of Photosynthesis: A Comprehensive Guide
Mastering Metabolism 101: A Beginner's Guide

Leyna's Textbook Answer Videos

00:55
Biology for AP Courses

A diploid cell has how many times the number of chromosomes as a haploid cell?
a. four times
b. half
c. one-fourth
d. twice

Chapter 10: Cell Reproduction
Leyna Stemle
02:21
Biology: The Dynamic Science

Space travelers of the future land on a planet in a distant galaxy, where they find populations of a carbonbased life form. The beings on this planet are of a vibrantly purple color. The travelers suspect that the beings secure the energy necessary for survival by a process similar to photosynthesis on Earth. How might they go about testing this conclusion?

Chapter 8: Photosynthesis
Leyna Stemle
03:23
Estadistica para biologia y ciencias de la salud

Utilice la técnica explicada en el Ejemplo 6.1 .1 para hallar un punto aleatorio inicial en la Tabla IV del Apéndice B. Utilice este punto inicial para asignar aleatoriamente tratamientos a las 20 plántulas de pino del Ejemplo 6.1.2. ¿A cuántas plántulas se les ha asignado el mismo tratamiento que el asignado por la aleatorización del Ejemplo 6.1.2?

Chapter 6: Inferencias sobre la media
Section 1: Muestreo aleatorio y aleatorización
Leyna Stemle
1

Leyna's Quick Ask Videos

03:39
Biology

Q3.25. Imagine that rainfall increases and lakes expand,
creating more loon territories. As the number of territories
increases, their value declines. All else being equal, how would
this change affect the outcome of the game, and why?
Hawks would increase in proportion, because the cost of fighting
(i.e., injury) would be larger.
Doves would increase in proportion, because the benefit of
victory would be reduced.
Doves would increase in proportion, because the cost of fighting
(i.e., injury) would be larger.
The proportions of neither Hawks nor Doves would change, because
territory availability isn't relevant to costs or benefits.

Leyna Stemle
03:58
Biology

If you were looking under the compound light microscope at an
onion root tip, in what stage of the cell cycle would the majority
of the cells be?
cytokinesis
metaphase
prophase
interphase
anaphase

QUESTION 2
A centromere holds together two:
non-sister chromatids.
centrioles.
sister chromatids.
centrosomes.
spindle fibers.

QUESTION 3
Apoptosis
can be used to remove damaged or malfunctioning cells.
increases the number of somatic cells.
occurs as telomeres increase in length.
is a process that repairs damaged DNA.
increases the number of gamete cells.

QUESTION 4
Proteins that are involved in the regulation of the cell cycle,
and that show fluctuation in concentration during the cell cycle,
are called
centromeres.
centrioles.
cyclins.
proton pumps.
kinetochores.

QUESTION 5
Plant cells and animal cells differ in cytokinesis because
animal cells need to build a cell wall, while plant cells do
not.
animal cells are living, while plant cells are not.
plant cells divide by mitosis, while animal cells divide by
meiosis.
plant cells need to build a cell wall, while animal cells do
not.
animal cells need to build a cell membrane, while plant cells do
not.

QUESTION 6
Cells that do not receive the correct signals to move from
G 1 into S phase will enter
G 0 and therefore will
immediately move into the mitotic phase.
stay in an undifferentiated state and become stem cells.
not undergo mitotic division unless it later receives the
go-ahead signal.
never be able to undergo mitosis.
be able to produce gametes through meiosis.

QUESTION 7
In an experiment, cells grown in a petri dish divided until they
formed a thin layer covering the bottom of the dish. When cells
were removed from the middle of the dish, the cells bordering the
open space began dividing until they had filled the empty space.
What does this experiment show?
Cells continue to grow as long as there is adequate space.
When cells come into contact with other cells, they stop
growing.
Cell division can be regulated by factors outside of the
cell.
All answers are valid and correct.
The controls on cell growth and division can be turned on and
off.

QUESTION 8
A tumor suppressor gene undergoes a mutation that causes it to
lose its normal function. What would be the most likely result of
this mutation?
the cell stops dividing permanently and will never re-enter the
cell cycle
the cell cycle halts and reverses back to the
G 0 stage
the cell cycle accelerates
the cell no longer responds to signals that cause it to stop
dividing or undergo apoptosis
the cell loses contact inhibition even when it is not surrounded
by other cells

QUESTION 9
A protein that promotes apoptosis would be considered a(n)
mutant tumor suppressor.
proto-oncogene.
oncogene.
tumor suppressor.
signal transduction pathway protein.

Leyna Stemle
02:37
Biology

MYP 5 Lab Report – Barnacle Lab Simulation (18 points)

Overview Summary
This activity is an inquiry-based lab where students investigate and discover how abiotic and biotic factors can limit the population growth within a controlled environment.
Students must be able to demonstrate how competition for natural resources in a closed environmental system can affect the population growth of the different species of barnacles. Students should also be able to explain how the availability of biotic and abiotic factors can be limiting on population growth.
Students should write up the following lab sheet, the graph and data table can be downloaded from the website of the simulation lab.

Barnacle Competition - Virtual Biology Lab
(Criterion B, strand i.):
Explain a problem or question to be tested by a scientific investigation

Objective:
The purpose of the experiment is to: (3 pts) ______________________________________________________________________________________________________________________________________________________________by ________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

Hypothesis (Criterion B, strand ii.):
Formulate a testable hypothesis and explain it using scientific reasoning

Hypothesis: (3 pts)
If _________________________________________________________________
Then ______________________________________________________________
Because ___________________________________________________________

(Criterion B, strand iii.):
Explain how to manipulate the variables and explain how data will be collected.

Variables: (3 pts)
Independent:
Dependent:
Controlled

Results (Criterion C strand i):
Present collect and transformed data

You can manipulate the variables by: (2 pts)
_________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

The data will be collected by: (2 pts)
____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

Copy the table and graph (take a screenshot) from the lab simulation onto this page. (2 pts)

Analysis (Criterion C strand ii):
Interpret data and explain results using scientific reasoning

The process revealed / showed (3 pts):
________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

Leyna Stemle
03:34
Biology


What are some implications of climate change for people and
other life on Earth? Think of all what you learnt in class! Mention
at least 3.
How can we respond to the grand challenge of climate change?
How can we mitigate and/or adapt to climate change?
If people are displaced from their homeland due to climate
change, should industrialized nations have to take them in, since
fossil fuel burning is responsible for their loss of homes?

Leyna Stemle
02:05
Biology

1. Suppose you traveled back in time and located the first
animals to have evolved feathers. You found that these animals were
tree-dwelling ectotherms, able to run quickly but unable to fly.
You also noticed that only males had feathers. Develop a hypothesis
to explain the evolution of these feathers.

Leyna Stemle
04:15
Biology

List two goods or services provided by ecosystems that have
market value.
List two goods or services provided by ecosystems that have
nonmarket value.
What three adaptations have prey developed to help them escape
predation?
List three benefits of biodiversity to humans.
Briefly explain how two forests with the same species richness
can be different in their species diversity.

Leyna Stemle
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