biology stuff Flashcards

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1
Q

List 5 structures in plant cells

A

Cell membrane, cell wall, cytoplasm, vacuole, nucleus

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2
Q

What is the epidermis in plants

A

Epidermis, in botany, outermost, protoderm-derived layer of cells covering the stem, root, leaf, flower, fruit, and seed parts of a plant. The epidermis and its waxy cuticle provide a protective barrier against mechanical injury, water loss, and infection.`

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3
Q

Explain why it is important to the plant that the tissue is transparent.

A

It allows light through, traps energy from light, needs light for photosynthesis, light reaches chloroplasts

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4
Q

Describe the function of stomata

A

For gas exchange, photosynthesis, controls rate of diffusion/transpiration

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5
Q

Describe how the ions move into the guard cells

A

Move against the concentration gradient using energy from respiration

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6
Q

Describe and explain how the change in ion concentration causes the guard cell volume to change.

A

higher ion concentration results in larger guard cell volume, causes lower water potential, causes water to move into guard cells across partially permeable membrane by osmosis

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7
Q

Suggest two environmental factors that can cause plants to wilt

A

Lack of water

high temperature

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8
Q

What are the two types of variation

A

There are two kinds of variation: continuous and discontinuous

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9
Q

What is Continuous Variation

A

Continuous Variation is when there are very many small degrees of difference for a particular characteristic between individuals and they are arranged in order and can usually be measured on a scale. Examples include height, mass, finger length

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10
Q

What is discontinuous variation

A

seen where there are obvious, distinct categories for a feature. - no intermediates between categories, the feature cannot usually change during life. - caused by a single gene/a small number of genes, with no environmental influence.

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11
Q

Describe how a blood clot forms

A

fibrinogen is converted to fibrin
Fibrinogen is soluble, fibrin is insoluble
Fibrin forms a mesh
Fibrin traps blood cells

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12
Q

State the importance of blood clotting.

A

Prevents blood loss

Prevents pathogens entering wound (viruses, bacteria, fungi, protozoa, and worms.)

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13
Q

define the term phenotype

A

the set of observable characteristics of an individual resulting from the interaction of its genotype with the environment.

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14
Q

state the two possible genotype for a person who has the phenotype blood group A

A

AA

AO

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15
Q

Explain the role of plant hormones in gravitropism

A

Auxin is a plant hormone
Auxin diffuses through the plant
Auxin stimulates cell elongation
Auxin is unequal distributed, more auxin accumulates lower parts

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16
Q

Explain how gravitropism enables a plant to survive

A

Roots growing down anchor the plant

plants growing up more likely to reach light

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17
Q

Describe how reflexes in animals differ from sensitivity in plants

A

Reflexes respond faster and are not a growth response

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18
Q

Define the term sense organ

A

groups of receptor cells responding to specific stimuli

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19
Q

state the names of two cell structures that are involved in making or secreting proteins

A

Ribosomes

mitochondria

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20
Q

state the substance that goblet cells secrete

A

Mucus

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21
Q

Describe the process of emulsification of fats.

A

Mix with bile
breaks up of large fat globules into smaller fat globules
Increases surface area of fat globules
Water enables dispersion of smaller fat globules

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22
Q

State the name of the organ in the alimentary canal where fats are emulsified

A

Small intestine

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23
Q

State the name of the structure in the Villi where digested fats are absorbed.

A

Lacteal

24
Q

Complete the sentence:

A nucleus containing a single set of unpaired chromosomes in a sperm is called a………….nucleus

A

haploid

25
Q

state where, in the female reproductive system, the event shown in Fig. 7.1 occurs

A

oviduct

26
Q

Describe what happens before an embryo is formed

A

digestive enzymes are released from sperm
Jelly coat is digested by enzymes
fusion of nuclei of gametes to form a diploid
Jelly coat hardens
Cell division / mitosis after formation of zygote

27
Q

What is an airway that allows passage of air into both lungs

A

Trachea

28
Q

What contracts to increase volume of thorax

A

diaphragm, intercostal muscles

29
Q

What is a muscle that contracts to lower the ribcage

A

intercostal muscles

30
Q

What are two common plant stimuli that cause responses

A

Gravity

Light

31
Q

Molecules of carbon dioxide that are produced in muscle cells are transported to the blood
Describe the pathway taken by these molecules of carbon dioxide

A
From muscle cell:
Produced in mitochondrion
Diffused in cytoplasm/ tissue fluid/ blood plasma
throguh memebrane
through capillary wall
From blood:
pulmonary artery/ heart
Travels to lungs
into alveoli 
Breathed out
32
Q

explain how capillaries are adapted for their functions

A

Thin wall for efficient diffusion and gas exchange
Small diameter
Many capillaries can fit into tissues throughout the body
large surface for diffusion
Capillary cells have pores to allow substances to pass in a and out of the blood easily

33
Q

explain how a molecule of carbon dioxide from the atmosphere reaches the site of photosynthesis in a leaf

A

Diffusion down concentration gradient

diffuses through stomata, between spongy mesophyll, into palisade, mesophyll cell

34
Q

Explain the role of mechanical digestion

A

breaks up food into smaller pieces without chemical change by teeth/muscles, to mix with digestive juices
increases surface area for enzyme action
speeds up chemical digestion
easier to swallow

35
Q

What is defined as the chemical reactions that break down food molecules in cells to release energy

A

respiration

36
Q

List the most likely number of chloroplasts in three types of cell in a leaf

A

epidermis: 0
Palisade mesophyll: 17
Guard cells: 6

37
Q

On a dry, sunny day, how does water vapour move through the stomata of a leaf

A

Out of the leaf by diffusion

38
Q

describe transpiration

A

Loss of water vapour from the leaves and steams of a plant

39
Q

A strip of the outer tissue including the phloem has been removed, how is transport in the plant affected

A

Amino acids and sucrose cannot pass to the roots

40
Q

what percentage of the gas in the blood is carbon dioxide

A

4.0%

41
Q

Which organ produces urea

A

liver

42
Q

What term is used for the transference of a gene from one organism to another

A

genetic engineering

43
Q

What result of deforestation will encourage the growth of soybean plants

A

increase in atmospheric carbon dioxide

44
Q

When we inhale (breathe in), what happens to the pressure in the thorax?

A

The pressure in the thorax decreases when we inhale.

45
Q

What happens when we exhale (breathe out)?

A

When we exhale, the diaphragm relaxes and moves upwards. This helps to reduce the volume in the thorax and push air out of the lungs

46
Q

What happens when we inhale (breathe in)?

A

When we inhale, the external intercostal muscles contract and the ribcage is pulled upwards and outwards

47
Q

During exercise, what happens to breathing in humans

A

During exercise, the breathing rate and the depth of breathing both increase.

48
Q

Tobacco smoke contains carbon monoxide. What problem does this cause?

A

Carbon monoxide from tobacco smoke combines with haemoglobin in the red cells, reducing the ability of the blood to carry oxygen

49
Q

what is a threat to biodiversity?

A

Habitat fragmentation reduces the number of species found in the area as resources become limited.

50
Q

What is the consequence of a bottleneck effect on species?

A

When the surviving population is very small it has lost lots of genetic information. This loss can prevent the population adapting to future environmental changes.

51
Q

Where is bile produced

A

The liver produces bile. It passes through the bile duct and into the small intestine.

52
Q

Which enzymes are produced by the stomach?

A

The stomach produces proteases

53
Q

Where is maltase produced?

A

Maltase is produced in the small intestine

54
Q

Which acid is produced by the stomach?

A

The stomach produces hydrochloric acid

55
Q

How is food moved through the gut?

A

Peristalsis is the process that moves food through the gut. It involves wave-like contractions of muscles in the gut wall, rather than waves of liquid.