Quiz on Heredity

Question 1

Dominant alleles

Answer 1

Gene that prevents the other genes from showing, Upper case letter

Question 2

Recessive alleles

Answer 2

A type of allele that when present on its own will not affect the individual. Two copies of the allele need to be present for the phenotype to be expressed.

Question 3

Homozygous Dominant

Answer 3

both genes of a pair are the same but are the dominant gene

Question 4

Homozygous recessive

Answer 4

both genes of a pair are the same but are the recessive gene

Question 5

Heterozygous

Answer 5

one dominant and one recessive gene

Question 6

The ideas of inheritance before Mendel

Answer 6

Before Mendel, people thought traits blended.Offspring inherit many traits from their parents but the specific details of inheritance eluded scientists for centuries. Early theories assumed a simple blending of traits between two parents. Aristotle noticed that one offspring sometimes looked more like one parent than the other and sometimes even more like a grandparent.

Question 7

Mendel’s three Laws

Answer 7

Law of Dominance, Law of Independent Assortment of alleles, Law of Segregation of alleles

Question 8

Law of Dominance

Answer 8

Some alleles are dominant while others are recessive; an organism with at least one dominant allele will display the effect of the dominant allele.

Question 9

Law of Independent Assortment of allele

Answer 9

Genes for different traits can segregate independently during the formation of gametes .

Question 10

Law of Segregation of alleles

Answer 10

• During gamete formation, the alleles for each gene segregate from each other so that each gamete carries only one allele for each gene.
• An organism inherits one copy of each gene from each parent. This means that when an organism produces gametes (sex cells such as sperm or eggs), the two copies of each gene are separated or segregated from each other, and only one copy of each gene is present in each gamete. The offspring inherit one copy of each gene from each parent, and the two copies of each gene come together to determine the traits of the offspring.

Question 11

how Mendel’s three laws are evident in the stages of meiosis I & meiosis II

Answer 11

Law of Segregation Anaphase 1, genes on chromosomes are random
Law of independent assortment Anaphase 1, chromosomes split randomly
Law of Dominance, If it is a dominant allele it will show

Question 12

Gametes

Answer 12

Gamete is a sex cell, result of meiosis, there are two gametes one from each parent one egg, one sperm cell

Question 13

How did Mendelian genetics lead to the predictability/probability of determining which alleles are inherited by the progeny or offspring of organisms?

Answer 13

His laws of inheritance, explains the predictability and probability of determining which alleles will be inherited by offspring. According to Mendel’s laws, an offspring receives one allele from each parent for a given trait, and the combination of these alleles determines the phenotype (observable characteristic) of the offspring. Through controlled cross-breeding experiments, Mendel was able to determine the probability of inheriting specific alleles, and he found that these probabilities followed predictable patterns. These patterns, known as Mendel’s laws, provide the foundation for understanding the inheritance of traits and the predictability of offspring genotypes.

Question 14

3:1 ratio Monohybrid

Answer 14

this will occur when two heterozygous parents each give one allele to their offspring, creating two possible phenotypes even though there may be multiple genotypes

Question 15

Non Mendelian crosses- what are they and why are they non-Mendelian

Answer 15

Non-Mendelian inheritance refers to the inheritance of traits that have a more complex genetic basis than one gene with two alleles and complete dominance

Question 16

Incomplete dominance

Answer 16

Incomplete dominance results from a cross in which each parental contribution is genetically unique and gives rise to progeny whose phenotype is intermediate. Incomplete dominance is also referred to as semi-dominance and partial dominance. Mendel described dominance but not incomplete dominance.

Question 17

Codominance

Answer 17

This means that neither allele is dominant over the other, and both are fully visible in the organism’s appearance or behavior. For example, if a plant has one allele for red flowers and another allele for white flowers, a codominant expression of the alleles could result in the plant having flowers that are both red and white, instead of a mix of pink flowers that might be expected from incomplete dominance.

Question 18

Test Cross

Answer 18

A test cross is a genetic experiment used to determine the dominant and recessive traits of an organism. It involves crossing an individual with unknown genotype (the “tester”) with a homozygous recessive individual. The offspring are then observed for their phenotype, allowing the inference of the tester’s genotype based on the dominant/recessive pattern of inheritance.

Question 19

Phenotypic ratios v/s Genotypic ratios – determining and writing these ratios.
What do these ratios tell us?

Answer 19

Genotype ratios are the combination of genes that an organism has (actual gene makeup) ex) PP, Pp, pp

Phenotype ratios are the physical appearance resulting from gene makeup ex) purple or white flower color

Question 20

How does sexual reproduction allow for evolutionary processes to enhance survival of living organisms leading to species diversity and thus biodiversity?

Answer 20

Sexual reproduction allows for evolutionary processes to enhance the survival of living organisms and increase species diversity through a process known as genetic recombination. During sexual reproduction, genetic information from two individuals is combined to create offspring with unique genetic compositions. This genetic diversity provides a greater pool of genetic variations, some of which may provide a survival advantage in changing environments. Over time, organisms with advantageous traits are more likely to survive and reproduce, passing their advantageous traits to the next generation. This process, known as natural selection, can lead to the evolution of new species and the diversification of existing species, increasing overall biodiversity. Additionally, sexual reproduction also allows for the repair and removal of harmful mutations through processes such as meiotic recombination and genetic crossing over. These mechanisms further contribute to the survival and adaptation of living organisms and the evolution of species over time.

Question 21

How do genetic diseases such as sickle cell anemia which are recessive alleles get passed on from one generation to another? How would you show this in a Punnett square?

Answer 21

The sickle cell anemia trait is found on a recessive allele of the hemoglobin gene. This means that you must have two copies of the recessive allele — one from your mother and one from your father — to have the condition.

Question 22

How is the Prunnett Square used for predicting probability ratios

Answer 22

The punnett square is a convenient way to show the results of any genetic cross. The male gametes are written at the of the column of boxes, female to the side. In each box you write the combination of the zygote (zygote, fertilized egg cell that results from the union of a female gamete (egg, or ovum) with a male gamete (sperm) ) that forms when the gene at the top of the column and to the left or right are together.

Question 23

Monohybrid crosses

Answer 23

crossing two heterozygous genes

Question 24

In the pGlo Lab you transformed E. coli into a colony of glowing bacteria. What did this experiment use for the glo gene?

Answer 24

This experiment used the GFP gene which comes from jellyfish. It is a gene for green fluorescent proteins.

Question 25

In your own words describe the role of genetic switches within organisms.

Answer 25

Genetic switches, also known as gene regulatory elements or regulatory sequences, are segments of DNA that control the expression of genes. They act as on/off switches, determining whether a gene is turned on or off, and thus, whether a particular protein is produced. If it’s on the gene is transcribed, if off then it isn’t.

Question 26

On a larger scale, how is genetic modification used by humans in the modern age?

Answer 26

Today, we can incorporate new genes from one species into a completely unrelated species through genetic engineering, optimizing agricultural performance or facilitating the production of valuable pharmaceutical substances. Crop plants, farm animals, and soil bacteria are some of the more prominent examples of organisms that have been subject to genetic engineering.

Question 27

Traits

Answer 27

Alleles are instructions for specific ones ex) eye color, height, hair color

Question 28

Genes

Answer 28

It takes at least a pair of these for a trait, what makes us different, sequence of multiple base pairs

Question 29

Alleles

Answer 29

Different version of a gene ex) same gene for hair, but different kinds of hair