Use of biological resources Flashcards
What is the role of bacteria (Lactobacillus) in the production of yoghurt?
-Ferment milk sugar (lactose) into lactic acid
-Give yoghurt its acid taste
What is selective breeding?
-involves selecting individuals with desirable characteristics & breeding them together to produce offspring with those traits.
Why is selective breeding a repeated process?
-not all offspring will show the desired traits, so only those that do are selected and bred together.
-this process is repeated over many generations to reliably establish a new breed with the desired characteristics.
What are some desired characteristics in selectively bred plants?
1.Disease resistance in food crops
2.Increased crop yield
3.Hardiness to weather (e.g., drought tolerance)
4.Better tasting fruits
5.Large or unusual flowers
Give an example of a plant that has been selectively bred in multiple ways.
Wild brassica has been selectively bred to produce:
-Cauliflower
-Cabbage
-Broccoli
-Brussels sprouts
-Kale
-Kohlrabi
What is inbreeding?
Inbreeding occurs when only the ‘best’ animals or plants, which are often closely related, are bred together.
What is the gene pool and how does inbreeding affect it?
-The gene pool is the total number of alleles (gene variants) in a population.
-Inbreeding reduces the gene pool, limiting the variety of alleles.
How does selective breeding in animals work?
-Animals with desired traits are bred together
-offspring with those traits are selected
-and bred repeatedly over generations.
Why are several parents often chosen in selective breeding?
-to avoid breeding siblings together in the next generation and reduce the risk of inbreeding.
What are common characteristics selected in animals?
-Cows, goats, sheep: High milk or meat production
-Chickens: Large eggs
-Dogs: Gentle nature
-Sheep: High-quality wool
-Horses: Fast pace & fine features
Give an example of an animal selectively bred in many ways.
-The domestic dog has been selectively bred from wolves to produce many breeds with different characteristics.
How do natural selection & artificial selection compare?
NS:-ON
-RIDOPWFTABATTEAS
-UTALTTO
AS:-OOWHI
-RIDOPWFTAUTHANNUTTSOTI
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Natural Selection: -Occurs naturally
-Results in development of populations with features that are better adapted to their environment and survival
-Usually takes a long time to occur
Artificial Selection: -Only occurs when humans intervene
-Results in development of populations with features that are useful to humans and not necessarily useful to the survival of the individual
-Takes less time as only individuals with the desired features are allowed to reproduce
