Inheritance and Traits

Question 1

What is dominant and what is recessive?

Question 2

What does it mean to be a carrier

Question 3

T or F : To have a recessive visible trait, you must have two copies of that gene. To have a dominant, you only need one dominant

Answer 3

True

Question 4

there is no universal mechanism by which dominant and recessive alleles act. T or F

Answer 4

True. There is a lot of unpredictability about it and we are still learning.

Question 5

T or F : dominant allele + dominant allele = dominant phenotype
dominant allele + recessive allele = dominant phenotype
recessive allele + recessive allele = recessive phenotype

Answer 5

This is correct. It’s true!

Question 6

T or F. Dominant phenotypes are more common than recessive phenotypes

Answer 6

False. Not always. A population with a lot of light colored eyes for example is common in places like Scandinavia.

Question 7

Dominant or Recessive genes are not better than the other. T or F

Answer 7

True. One is not better than the other.

Question 8

What is a broken allele?

Answer 8

An allele that doesn’t work properly

Question 9

The environment does not affect genetics, traits

Answer 9

F: height, tongue rolling, etc. can be affected by environment as well as hereditary traits.

Question 10

Dimples are considered an “irregular” dominant trait

Answer 10

True

Question 11

Freckles are controlled primarily by the MC1R gene.

Answer 11

True

Question 12

What is an allele

Answer 12

Different forms of a gene, which produce variations in a genetically inherited trait. (Different alleles produce different hair colors—brown, blond, red, black, etc.)

Question 13

What are genes?

Answer 13

Genes are parts of DNA and carry hereditary information passed from parents to children. Genes contain blue‐print for each individual for her or his specific traits.

Question 14

What is dominant?

Answer 14

Dominant version (allele) of a gene shows its specific trait even if only one parent passed the gene to the child.When a child inherits dominant brown‐hair gene form (allele) from dad, the child will have brown hair.

Question 15

What is recessive?

Answer 15

Recessive gene shows its specific trait when both parents pass the gene to the child.
When a child inherits recessive blue‐eye gene form (allele) from both mom and dad, the child will have blue eyes.

Question 16

What is homozygous?

Answer 16

Two of the same form of a gene—one from mom and the other from dad.Inheriting the same blue eye gene form from both parents result in a homozygous gene

Question 17

what are heterzygous?

Answer 17

Two different forms of a gene—one from mom and the other from dad are different.

Question 18

What is a genotype?

Answer 18

Internal heredity information that contain genetic code.

Question 19

What is a phenotype?

Answer 19

Outwardly expressed traits or characteristics. Both having or not having a widow’s peak are phenotypes

Question 20

What is mendelian inheritance?

Answer 20

A simple genetic rule where a gene only comes in dominant or recessive forms. Some genetic traits follow Mendelian Inheritance, while other genetic traits follow different inheritance patterns or rules.

Question 21

What is Sex-linked Mendelian Inheritance?

Answer 21

traits that are located on the autosomes but are influenced by the gender of the individual.

Question 22

Differentiate between phenotype and genotype?

Question 23

What are platelets?

Answer 23

fragments of cytoplasm which stops us from bleeding. hemophilia can affect this.

Question 24

hemophilia is sex linked recessive disorder T or F

Answer 24

True.

Question 25

What is a sex chromosome?

Answer 25

X or Y chromosome. It's usually the last two.

Question 26

T or F: Everyone has a Y chromosome

Answer 26

False. Everyone has an X chromosome.

Question 27

There are genetic disorders where you can have extra copies of sex chromosomes. True or False.

Answer 27

True

Question 28

Most sex like chromosomes are on the X chromosome.

Answer 28

True.

Question 29

Colorblindness is also a sex lined recessive disorder.

Answer 29

True.

Question 30

Why was the fruitfully significant to sex and classic genetics?

Answer 30

It showed the first demonstration for sex linked traits such as drosophila. mutations in the eye color made it white. this was a sex linked disorder and was linked to mating.

Question 31

What is linkage?

Answer 31

“Linkage” refers to the physical connection that exists between genes whose loci are on the same chromosome. Genes on the X chromosome are all linked to each other—thus they are X-linked.

Question 32

X-linked traits is that males always receive their X chromosomes from their mothers, so they also receive any X-linked traits from their mothers. Their fathers have no contribution for those genes (though, of course, they do for the genes on all of the other chromosomes). True or False?

Answer 32

True

Question 33

X-linked recessive traits appear far more commonly in females than in males.

Answer 33

False. X-linked recessive traits appear far more commonly in males than in females.

Question 34

There are no Y Linked disorders. T or F

Answer 34

False. There are a few genes which are Y-linked (or holandric). Y-linked genes are carried on the Y chromosome, and are thus passed directly from father to son. Every son has a copy of his father’s Y chromosome. In any pedigree showing unbroken lines of male descent, all of the connected males have copies of the same Y chromosome, and thus share any Y-linked characteristics.

Question 35

FACT: Cryptorchidism is a genetically determined condition in which one or both testicles fail to make this voyage, and remain in the abdomen. (This is generally surgically corrected very early, because not only is a cryptorchid male sterile, but the undescended testicles are at increased risk for testicular cancer). The genes for this condition are autosomal; males and females each carry two alleles. But only males can possible exhibit the condition, because only males show the normal condition for testicle behavior and position.

Answer 35

Do you understand this?

Question 36

Describe sex limited and sex influenced genes traits

Answer 36

These are autosomonal. They are not on the sex genes. they are expressed phenotypically.

Question 37

Where are x linked genes found?

Answer 37

on the X chromosome

Question 38

Where are y linked genes found?

Answer 38

on the Y chromosome

Question 39

Where are sex limited and sex influenced traits found?

Answer 39

on autosomes (non sex chromosomes)

Question 40

X linked facts

Answer 40

Hemophilia in humans is determined by a recessive X-linked allele. An unaffected woman whose father has hemophilia man marries a normal man. Determine the probability of their child having hemophilia. What is the probability of a son having hemophilia? What is the probability of a daughter having hemophilia?

Question 41

Y linked facts

Answer 41

Never occur in females Passed from father to all sons Not dominant or recessive because of homozygosity

Question 42

Facts about sex limited traits

Answer 42

Expression occurs only in one sex 100% expression in one sex and 0% expression in the other Usually due to anatomical or hormonal differences between the sexes.

Question 43

Facts about sex influenced traits

Answer 43

Expression is influenced by the sex of the individual Hormones affect expression The trait may be dominant in one sex and recessive in the opposite sex

Question 44

Steps to solve crosses on punnet squares

Answer 44

Steps * Write down symbols for the alleles * Determine the genotypes of the parents * Identify the gametes produced by the parents * Make a Punnett square of the appropriate size * Determine the genotypes of the offspring * Determine the phenotypes of the offspring * Answer the question depending on what is asked

Question 45

Names some recessive genes

Answer 45

straight hair, attached earlobes, short eyelashes, red hair color, non-roller tongue, straight hairline, hitchhikers thumb, non PTC taster

Question 46

Names some dominant genes

Answer 46

curly hair, free earlobes, long eyelashes, non-red hair color, roller tongue, widows peak hairline, straight thumb, PTC taster