Chapter 18 - Applied Genetics Flashcards Preview

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What is selective breeding?

Selective breeding is the process of breeding animals or plants with desirable traits and to concentrate those desirable traits in their offspring.


What is selective breeding sometimes known as?

Artificial Selection.


What does selective breeding of animals produce?

Selective breeding of animals produces breeds (e.g. Holstein, Jersey, etc).


What does the selective breeding of plants produce?

The selective breeding of plants produces cultivares or varieties (E.G. Kerr's Pink and Golden Wonders are varieties of potatoes).


What can the selective breeding of plants and animals be divided into?

The selective breeding of plants and animals can be divided into inbreeding and crossbreeding.


What is Inbreeding?

Inbreeding is the mating of closely related animals or plants.


(ADVANTAGE) What does inbreeding fix?

Inbreeding fixed certain desirable traits, such as high milk yields in purebred dairy cows.


(ADVANTAGE) What does inbreeding create among the offspring?

Inbreeding creates uniformity among the offspring.


(ADVANTAGE) What does inbreeding produce?

Inbreeding produces pedigree animals (purebred animals) whose lineage is known (ancestry) and are registered with a breed society or stud look.


(ADVANTAGE) What is inbreeding used to produce in plants?

Inbreeding is used to produce stock or purebred lines in plants.


(DISADVANTAGE) What does inbreeding increase the inheritance of?

Inbreeding increases the inheritance of similar genes, leading to an increase in homozygous genotypes (BB or bb).


(DISADVANTAGE) What does inbreeding concentrate?

Inbreeding concentrates undesirable recessive traits.


(DISADVANTAGE) What does inbreeding increase the chances of?

Inbreeding increases the chances of lethal genes occuring, which can result in the death of the organism.


(DISADVANTAGE) What has inbreeding led to in Holsteins?

Inbreeding has led to an increase in calving intervals in Holsteins


(DISADVANTAGE) What can inbreeding make more animals susceptible to?

Inbreeding can make more animals susceptible to disease.


(DISADVANTAGE) What does inbreeding lead to a loss in?

Inbreeding leads to a loss in genetic diversity.


What is Cross Breeding?

Cross breeding involves the mating of animals or plants from two different breeds, varieties or species.


What is Cross Breeding also known as?

Cross Breeding is also known as out breeding.


(ADVANTAGE) In Cross Breeding, offspring often inherit what?

In Cross Breeding, offspring often inherit favourable genes from both parents, which leads to increased productivity. This is known as hybrid vigour.


(ADVANTAGE) What does Cross Breeding often lead to?

Cross Breeding often leads to better health traits and lifespan in the offspring.


(ADVANTAGE) What does Cross Breeding reduce?

Cross Breeding reduces the risk of recessive genes appearing in the phenotype.


(ADVANTAGE) What does Cross Breeding increase the number of?

Cross Breeding increases the number of heterozygous pairs of genes.


What is Hybrid Vigour?

Hybrid Vigour is the increased productivity displayed by the offspring of genetically different parents. It is often known as heterosis.


(DISADVANTAGE) The resulting offspring, when horses are crossed with donkeys, are what?

When horses are crossed with donkeys, the resulting offspring are infertile.


(DISADVANTAGE) What does Cross Breeding result in?

Cross Breeding results in loss in uniformity of the offspring.


(DISADVANTAGE) What is there a loss of in Cross Breeding?

In Cross Breeding, there is a loss of hybrid vigour, with subequent crossing of the hybrids or crossbred animals.


(DISADVANTAGE) What can crossbred animals not be registered as? Why?

In Cross Breeding, Crossbred animals cannot be registered with a breed society or breed register, as they are not purebred.


How are F1 Hybrids produced?

F1 Hybrids are produced by crossbreeding two genetically different purebred parents.


What are the F1 Hybrids usually?

The F1 Hybrids are usually stronger, have greater disease resistance and produce higher yields.


In F1 Hybrid Seed Varieties, the parent plants are what?

In F1 Hybrid Seed Varieties, The parent plants are inbred over several generations.