Biology Flashcards 5 - Genetic screening, Pregnancy, selective breeding, genetic engineering, adaptations, carbon cycle, biodiversity, enzymes, blood
What are alleles?
What are the two types?
Different version of the same gene.
Alleles can be dominant and recessive.
What is the purpose of genetic screening?
It provides valuable information about an individual person’s genetic makeup, helping in early detection, reproductive planning, personalised medicine, and public health interventions.
What are the three traits or diseases that can be tested for?
- Alzheimer’s
- Hereditary breast and ovarian cancer
- Cystic fibrosis
What is Amniocentesis?
It is carried out at around 15-16 weeks of pregnancy. It invovles taking some of the fluid from around the developing fetus. This fluid contains fetal cells, which are used for genetic screening.
What is the risk of screening embryos?
Risk of a miscarriage
What is chorionic villus sampling?
This is done between 10+12 weeks of pregnancy by taking a small sample of tissue from the developing placenta. This again provides fetal cells to screen.
What is meant by nature in evolution?
People inherit characteristics from both of their parents and each person gets a different combination of features. This is called genetic variation.
What is meant by nurture in terms of evolution?
Other characteristics are affected entirely by a person’s environment. This is called environmental variation
What is selective breeding?
Selective breeding is a process where humans breed plants and animals for desired characteristics
What are the limitations of selective breeding (Two)
- Reduces the number of genes in a population
- Reduced alleles within a population
What is genetic engineering?
Introducing a gene from one organism into the genome of another organism to introduce desirable characteristics.
What is the genetic engineering process? (Eight steps)
- Human cells contain a gene for making insulin
- Bacteria cells contain a ring of portable DNA called a plasmid
- Extract DNA from some human cells
- Use an enzyme to cut the insulin gene out of the DNA
- Use the enzyme to cut the bacteria DNA plasmid
- Use a different enzyme, stick the human insulin gene into the bacteria plasmid
- The plasmid holding the insulin gene is put into bacteria
- The bacteria reproduce and start to make insulin
Who started classification?
Carl Linneaus
How did Carl Linneaus classify organisms? (Seven)
He grouped organisms depending on their physical appearance and characteristics:
Kingdom
Phylum
Class
Order
Family
Genus
Species
What are the three domains called
Archaea
Bacteria
Eukarya
What can light intensity do to living organisms? (Two)
- Light is needed for photosynthesis and affects the distribution of plants + animals
- Plant adaptations for growing in low light intensifies = more chlorophyll + bigger leaves
What is temperature needed for for living organisms? How can low temperatures impact creatures? (Two)
- Temperature is needed for photosynthesis
- Low temperatures = small plants affecting the number of herbivores which affects the number of carnivores
What is a quadrat used for?
To measure the number of an organism in a given area
What is a line transect?
They are a line between 2 areas marked with a long measuring tape along which quadrat sampling occurs at regular intervals
What adaptations do polar bears have to survive? (Four)
- Small ears to reduce heat loss
- Layer of blubber and thick fur for insulation
- Greasy waterproof coat
- White fur - camouflage
What adaptations do camels have to survive? (Three)
- Large flat feet to spread their weight
- Low breathing = less water loss from respiration
- Slit-like eyes and nostrils to keep the sand out
What are the adaptations of cacti? (Three)
- Cacti have spines instead of leaves to reduce water loss
- Thick waxy cuticle
- Water storage tissue, thick stem to store water
Go through the carbon cycle (Seven)
1). CO2 is taken in by plants for photosynthesis
2). Plants release CO2 through respiration
3). The carbon taken in by plants is then eaten by animals
4). Animals release CO2 through respiration
5). Animals die and their remains are fed on by microbes
6). Decay-microbes release CO2 through respiration
7). Combustion releases CO2
What is Biodiversity?
Biodiversity is all the different types of life in one specific area
Why is biodiversity important?
It is important because it supports all of the essential processes for every living thing on Earth. Without this range of species we cannot have the healthy ecosystems that we rely on food.
What are the three ways to speed up diffusion?
- Temperature: As the temperature increases, the particles in a gas or solution more around more quickly
- Surface area - folding the membrane of a cell increases the area over which diffusion can take place e.g. alveoli, villi
- Concentration gradient: When there is a steep big concentration gradient the rate is quicker
What does ‘specialised cell’ mean?
How is a root hair cell adapted to its function
- They are designed to carry out a particular role in the body
Root hair cells
- They have a large surface area which speeds up the movement of water to the plant
- They have a permanent vacuole which speeds up the rate of osmosis
- They have mitochondria which transfer energy
What happens to animal and plant cells in these solutions?
1). Hypotomic solution
2). Isotonic solution
3). Hypertonic solution
Animal cells
1). Bursts
2). Normal
3). Shriveled
Plant cells:
1). Normal
2). No change (flaccid)
3). Plasmolised
What do you do to mm to get to micrometer?
What do you do to micrometer to get to nanometer?
divide by 1000
divide by 1000
What are 2 factors that affect the rate of enzyme action?
What are enzymes made of?
Can you kill enzymes?
- Temperature and pH
- Long chains of amino acids to create a protein
- No, because they are not living
What are the enzymes that break down these:
1). Proteins
2). Carbohydrates
3). Lipids
1). Protease
2). Carbohydrase
3). Lipase
What are examples of:
1). Protease
2). Carbohydrase
3). Lipase
Where are these found?
1). Pepsin
2). Amylase
3). Lipase
1). Stomach, pancreas, small intestine
2). Mouth, pancreas, small intestine
3). Pancreas, small intestine
Where is bile stored?
What does bile do?
What produces bile?
- Gallbladder
- It is an alkaline to neutralise the hydrochloric acid from the stomach
& breaks down large drops of fat into smaller ones, this is known as emulsification - The liver
What do platelets do?
What do red blood cells do?
What do white blood cells do?
- They clot blood and stops you getting an infection when you cut yourself.
- They carry oxygen around the body (to the tissues)
- Fight and kill bacteria
What are the adaptations of:
1). Platelets (Two)
2). Red blood cells (Three)
3). White blood cells (Three)
Platelets:
- No nucleus
- Small fragments of cells
Red blood cells:
- No nucleus
- Bioconcave disc
- Contain haemoglobin - binds to oxygen
- Has a big surface area
White blood cells:
- Contains a nucleus
- Produces antibodies + antitoxins
- Engulf pathogen (bacteria)
What does Plasma do?
What are its adaptations? (One)
Transports:
- Glucose, amino acids
- Hormones, proteins
- Urea
Makes the blood watery so it can flow
