BSC2011L quiz 2

What types of genes are typically activated during determination?

regulatory genes

If you were to do a χ2 test on the data, what would the expected value be for the individuals with white fur and blue eyes?

9.375

What type of data is analyzed using a chi-squared ( χ2 ) test?

counts

What is the expected phenotypic ratio in the F2 assuming independent assortment?

9:3:3:1

Mendelian inheritance

A locus is where a gene is located on a chromosome. There are 2 alleles that can express that gene. A dominant or recessive allele

The allele for white hair in mice is autosomal recessive (b), while the allele for black hair is autosomal dominant (B). A white, female mouse mates with a black, male mouse. If the offspring are half black and half white, what are the possible genotypes for the black, male mouse?

Bb only

Hoxgenes

Control embryonic development of body parts •Contribute to differentiation •Observed in fruit flies, mice, and humans, just to name a few!

When does mitosis occur?

During growth, repair, cloning and asexual reproduction. two daughter cells with same amount of chromosomes as parent cell

What is the difference between an allele and a gene (locus)?

an allele is a particular version of a gene

Based on what you know, what kind of cross is being done here?

autosomal dihybrid cross

The allele for white hair in mice is autosomal recessive (b), while the allele for black hair is autosomal dominant (B). A white, female mouse mates with a black, male mouse. What are the possible genotypes for the white, female mouse?

bb only

The rest of the questions are based on the following scenario: You have guinea pigs from two pure breeding lines. One line has black fur and red eyes and the other line has white fur and blue eyes. When you cross them, all the F1 guinea pigs have black fur and blue eyes. When you cross the F1s to one another, you get a total of 50 F2 offspring. There are 31 with black fur and red eyes, 15 with white fur and blue eyes, 2 with white fur and red eyes, and 2 with black fur and blue eyes. There are approximately equal numbers of males and females in each phenotypic category. Which alleles are dominant?

black, blue

A cell in an embryo that still resembles the original cells of that embryo but will eventually form the spinal cord is ___.

determined only

Hox genes play an important role in _____________ development and contribute to ____________.

embryonic, differentiation

when does meiosis occur?

formation of gametes 2 rounds of cell division and end result of 4 daughter cells with half as many chromosomes

cell differentiation and determination are controlled by

gene expression

in many sex linked recessive disorders

males are susceptible to inherit the disorder because there is only one X-chromosome present. i.e. color blind

Girardia tigrina (formerly Dugesia tigrina) have an abundance of ________________ allowing them to regenerate body parts

neoblasts

two problems with the blending inheritance model

not all characteristics show up as intermediate in offspring all variations characteristics would be lost within a few generations

What does the law of segregation state?

only one allele per locus is present in each gamete it states that a parent passes one of its two alleles a particular locus to each of its offsprings randomly.

Neoblasts

pluripotent adult stem cells undifferentiated cells with the ability to differentiate into specialized cell types

The production of a new structure, following the removal of an existing structure, in an adult animal is known as ___.

regeneration

cell determination

stem cells become committed to develop into only one type of cell (cell fate) regulatory genes are expressed

cell differentiation

the process by which a cell becomes specialized for a specific structure or function.

Why is it important to use individuals from pure breeding lines to start crosses?

to ensure the individuals are homozygous