Genetics Test 2: Dr Shan

Hemizygous

Having one allele of a given gene; X^A Y

1/3 AA, 2/3 Aa

You and your parents do not express an autosomal recessive trait whereas your brother does. What are possible genotype probabilities for you

Zygotene stage of prophase 1

At what stage of mitosis does pairing of the homologous chromosomes occur

Mom

Who is the mitochondria inherited from?

Metacentric

centromere in middle

Acrocentric

centromere close to end

Telocentric

centromere at end

DNA, nucleosome, solenoid, loop, rosette, coil, 2x10 coils or chromatid

Steps of dna packaging

Rosette

At what stage of DNA packaging does mitosis begin

Interphase S phase

DNA replication

Equational division

Division that occurs during mitosis

3,2

A mature seed will have a ———n endosperm and a ———n zygote

Autosomes, sex chromosomes

two types of chromosomes

1:1:1:1

GR for drosophila eye color

PR for drosophila eye color

Sex and eye color- 3:1:1
Eye color- 3:1
Sex-1:1

Prophase I

leptotene, zygotene, pachytene, diplotene, diakinesis

Leptotene

chromosomes condense

Zygotene

Pair of homologous chromosomes

Pachytene

Crossing over occurs

Diplotene

chiasmata become visible

Diakinesis

Nuclear membrane disappears

non-sister chromatids

Cross over events occur between ...

Educational and equational division

What type of division occurs in Meiosis I and II

second meiotic division

Which division occurs between the secondary oocyte and ootid

1. With the secondary oocyte
2. With the ootid

When is the first polar body formed? When is the second polar body formed?

Meiosis

When does pairing of homologous chromosomes occur

Parthogenesis

Small white turkeys and honey bee

2

What would A be for a Drosophila Melanogaster Female? A= 3 autosomes

Calvin Bridges

Model shows how sex is determined based off the ratio of X chromosomes to the number prior to A

Metaphase 1: 2N, 4C

N and C at metaphase I of meiosis I

1N, 2C

What would N and C be at Metaphase 2 of Meiosis I

holandric trait

a trait inherited via the Y chromosome; hairy pinna

Pollen grain

What does a diploid microspore mother cell become after it undergoes meiotic divisions during sporogenesis

One survives and becomes an embryo sac

Of the four haploid megastores that are formed from the diploid megaspore mother cell, how many survive? What happens to the surviving megaspore(s)?

Humans: 22; Chickens: 38; Drosophila: 3

How many autosomal pairs do humans, chickens, and Drosophila Melanogaster have?

ZZ or XX

A male chicken's sex chromosomes are homogametic

X

Is the X or Y chromosome larger

First meiotic division

Which division occurs between the primary and secondary spermatocyte?

Barr body

Inactivated X chromosome in female somatic cells

1

Barr body for klinefelters syndrome (XXY: 2-1)

0

Barr body for Turner syndrome (X: 1-1)

2

Super female Barr body (XXX: 3-1)

0

Super male Barr body (XYY: 1-1)

Female because inactivation of the X chromosome occurs early on in embryonic development at random

What sex are calico cats always and why (X^B X^b)

Reciprocal cross

Tells if the genes are sex-linked; the P generation will not give similar results if so. If not, gives similar results

Sex-linked; autosomal

A fruit fly red and white eye color is a ——— trait, whereas a fruit fly normal and vestigial wings is a ——— trait.

14 bivalents

If a cell has 28 chromosomes how many bivalents would form during Zygotene phase of prophase I

One rosette (6 loops)

What step of dna packaging occurs to form one coil?

Sex influenced

Sex limited

Barring also

Microspore

male gametophyte (pollen grain)

10

How many chromosomes in each cell during prophase

20

How many DNA molecules will be found in each cell during prophase

20

How many chromosomes in each cell at the end of anaphase

20

How many DNA molecules in each cell at the end of anaphase

10

How many chromosomes in each cell after telophase/ end of cytokinesis? How many DNA molecules

lysosome, mitochondria, nucleolus

eukaryotic only

sex-determining chromosomes

-act like homologous chromosomes during meiosis so each gamete will get one sex chromosome

Prophase

-chromosomes coil up and condense; centrioles divide and move apart
-cohesins join sister chromatids of duplicated chromosome; tubulins assemble into spindle microtubules

Prometaphase

chromosomes are clearly double structures; centrioles reach the opposite poles; spindle fibers form
-microtubules attach to kinetic horse

Metaphase

-centromeres align on metaphase plate
-kinetochores are motionless in relation to poles of cell

Anaphase

centromeres split and daughter chromosomes migrate to opposite poles
-cohesins break down; kinetochores move toward poles of cell

Telophase

daughter chromosomes arrive at the poles; cytokinesis commences
-spindle microtubules disassemble

Anaphase I

When does chromosome number reduction take place

S and G2

Sister chromatids present in all or part of phase; DNA content per cell doubled in all or part of phase

Anaphase ii

When does separation of sister chromatids occur in meiosis

Novel combinations of genes

Can arise from reciprocal exchange of DNA between homologs during prophase I

Proband

Which term describes the individual in a pedigree whose phenotype was first brought to the attention of a medical researcher?

Autosomal recessive traits

If neither parent expresses the trait, but the offspring does, both parents must be heterozygous for the trait

Rare X-linked recessive

What is the most likely mode of transmission for a trait that is not expressed in parents but is expressed by one half of the sons?

all daughters will not have the disorder and all sons will have the disorder

Which of the following statements would be the most likely scenario of offspring of a woman exhibiting an X-linked recessive disorder and a man that does not exhibit the trait

Sex linked recessive

A cross was made between homozygous wild-type female Drosophila and yellow-bodied male drosophila. All of the resulting offspring were phenotypically wild type. Offspring of the F2 generation had the following phenotypes pictured. Which is the correct mode of inheritance for this gene

True

True or false: for X-linked traits in drosophila, the male phenotype is determined by the maternally inherited allele

100%

Pattern baldness is a sex influenced trait with heterozygous males exhibiting the trait. What would be the probability of the sons exhibiting the trait from a woman with pattern baldness and a male without pattern baldness

sex-limited traits

traits that are expressed in only one sex

XO males and XX females

Male and female gametes have dissimilar chromosome numbers

ZW female, ZZ male

Females produce two types of gametes

XX/XO and XX/XY

Males produce two types of gametes

XX/XY and ZW/ZZ

Male gametes and female gametes have equal chromosome numbers

Any of them

In what stage and parent could nondisjunction cause a child with Turner syndrome

The fly would be a male due to X:A ratio of 1/2

Assume you are told that a particular organism has the XO chromosome complement. You are also told that the autosomal complement is a normal 2n. You know that in humans the XO complement is female determining. What would the sex of this fly be and why