Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Alex's Genetics > Lecture 20b > Flashcards

Lecture 20b Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q

What is Locus Heterogeneity?

A

When a disease can be caused by mutations in two or more different genes.

Basically, there are several genes that could have a mutation in one of them and cause the disorder.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is an example of a disease that exhibits Locus Heterogeneity?

A

Hemophilia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

T/F: Blood clotting only involves one protein.

A

False! Blood clotting involves a cellular cascade that involves several different proteins.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Name the proteins that can be responsible for Hemophilia.

A

Hemophilia A, B, and C.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

When is Hemophilia A observed?

A

When there is a defect in clotting factor VIII

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is Hemophilia B caused by?

A

Caused by a defect in clotting factor IX

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

T/F: Both Hemophilia A and B are Y-linked recessive disorders.

A

False! Both Hemophilia A and B are X-linked recessive disorders.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is Hemophilia C caused by? Where is it found on?

A

Caused by a defect in clotting factor XI. Found on chromosome 4.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

In terms of Multifactorial and Polygenic Disorders, what do twin studies allow for?

A

Allow us to learn the relative importance of genetics vs [epigenetics + environment].

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

In terms of Multifactorial and Polygenic Disorders, what do we observe with monozygomatic twins?

A

These are identical twins, so they contain the same genes. We can see that in many cases, one can have the disorder and the other does not, showing the importance of the environment + epigenetics.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

T/F: Almost all types of cancers are mendelian diseases.

A

False! Almost all cancers are multifactorial and polygenic disorders. Chronic Myelogenous Leukemia is one of the few single gene cancers.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Multicellular organisms begin their lives as a ____________ ______ which then undergoes _______ ___________, _______ _____________, and changes in _____________ characteristics.

A

fertilized egg, cell division, cell migration, cellular

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What does Developmental Genetics study?

A

Studies the genes that orchestrate the changes that occur during development.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

T/F: The development field is quite far along compared to DNA replication or transcriptional regulation.

A

False! The development field is not as far along as fields such as DNA replication or transcriptional regulation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Why has the Developmental Genetics field established concepts and paradigms?

A

These concepts and paradigms may prove widespread during development or may turn out to only apply to one or a few situations; we don’t know yet

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Since developmental biologists cannot experiment on humans, what do they study?

A

Model organisms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What does multicellular development in plants and animals follow?

A

Follows a body plan or body pattern

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Define Body Pattern.

A

The body pattern is the arrangement of cells and their specialization.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

The progressive growth of a fertilized egg into an adult organism involves 4 types of cellular events. Name them.

A

Cell division, cell movement, cell differentiation, and cell death.

20
Q

The coordination of the 4 types of cellular events leads to what?

A

Leads to the formation of a body with a particular pattern.

21
Q

What does the generation of a body pattern depend on?

A

Positional information

22
Q

How does Positional Information impact body pattern?

A

Each cell becomes the appropriate cell type based on its position relative to the other cells.

23
Q

What are the 4 ways in which Positional Information affects cell?

A

1) A cell may be stimulated to DIVIDE into 2 daughter cells.
2) A cell may be stimulated to DIFFERENTIATE into another cell type.
3) A cell may be stimulated to MIGRATE from one region to another.
4) A cell may be stimulated to DIE.

24
Q

When a cell is stimulated to die, what is the process called? Why is this necessary?

A

Programmed cell death is known as Apoptosis. It is necessary to sculpt tissues and organs in normal development.

25
Q

What are Morphogens?

A

Molecules that convey positional information to cells and influence the developmental fate of cells.

26
Q

Morphogens act in a ___________-____________ manner and often have a critical ________________ _______________.

A

concentration-dependent, threshold concentration

27
Q

What happens for morphogens above the threshold concentration? What about below?

A

Above the threshold concentration, they exert their effect and restrict a cell into a particular developmental pathway.

Below the threshold concentration, they are ineffective.

28
Q

Generally speaking, what does the Morphogen gradient lead to?

A

Leads to two cell types, ones that are effective and ones that are ineffective.

29
Q

What is Induction? Why does this happen?

A

The process by which a cell or group of cells governs the developmental fate of neighboring cells.

This happens from the cells responding to morphogens if the morphogen exceeds the threshold concentration.

30
Q

Name the 3 molecular mechanisms of positional information.

A

1) Asymmetric distribution (gradient) of morphogens in an oocyte.
2) Asymmetric synthesis and extracellular distribution of a morphogen in an embryo.
3) Cell-to-cell contact conveys positional information.

31
Q

From cell-to-cell contact, how is positional information conveyed? What does each cell make?

A

Conveyed by cell cohesion.

Each cell makes its own cell adhesion molecules (CAMs)

32
Q

Most animals are bilaterians. What does this mean?

A

They have left-right symmetry.

EX: We have a right and left arm. This is symmetry.

33
Q

Development in bilaterians generally proceeds in 4 overlapping stages. Name them.

A

1) Formation of body axes
2) Segmentation of the body
3) Determination of structures within segments
4) Cell differentiation

34
Q

What are the main/most popular invertebrate model organisms?

A

Caenorhabditis elegans & Drosophila melanogaster

35
Q

Describe Caenorhabditis elegans.

A

A simple organism consisting of ~1,000 somatic cells. The pattern of cell division and the fate of each cell is known.

36
Q

Describe Drosophila melanogaster.

A

It has many mutant strains with altered developmental pathways. It is large enough to conduct transplantation experiments on.

37
Q

Describe the LIFE CYCLE of the Nematode Caenorhabditis elegans.

A

The embyro develops within the eggshell and hatches when it reaches 550 cells. It takes about 3 days for a fertilized egg to develop into an adult worm.

38
Q

What are 3 advantages to working with Caenorhabditis elegans?

A

1) Very inexpensive to maintain
2) Well-suited for siRNA (RNAi)
3) Well-suited for work on meiosis

39
Q

How is Caenorhabditis elegans well-suited for siRNA (RNAi)?

A

The nematode can be soaked in, injected with, or fed bacteria that express the double-stranded RNA of interest, and the siRNA will knock down the gene in every cell of the body.

40
Q

How is Caenorhabditis elegans well-suited for work on meiosis?

A

Because a large portion of the cells are in the germ cell lineage. Research into meiosis is further simplified since every germ nucleus is at the same given position as it moves down the gonad, so is at the same stage in meiosis.

41
Q

What two genders can a Caenorhabditis elegans be?

A

A male or a Hermaphrodite.

42
Q

In Caenorhabditis elegans, an adult male is composed of ________ somatic cells. It produces about ________ sperm.

A

1,031 and 1,000

43
Q

In Caenorhabditis elegans, an adult Hermaphrodite is composed of _______ somatic cells. It produces about ________ gametes (both sperm and eggs).

A

959 and 2,000

44
Q

Describe the pattern of cellular development in Caenorhabditis elegans.

A

It is extremely invariant (doesn’t change) from worm to worm.

45
Q

Define Cell Lineage.

A

A series of cells that are derived from each other by cell division.

46
Q

What is the disadvantage of Caenorhabditis elegans?

A

Others animals do NOT have precise invariant (exact) lineages so Caenorhabditis elegans is only a good system for a small number of research areas, such as meiosis.

Alex's Genetics (38 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions