B1

Question 1

Calculating magnification

Answer 1

The magnification is how many times, the object has been enlarged. To calculate the magnification, you will need to multiply the magnification of the ocular lens with the magnification of the objective lens. See below for the equation.

Question 2

Animal and plant cell similarities

Answer 2

All living things are made up of cells. The structures of different types of cells are related to their functions.
Animal cells and plant cells have features in common, such as a nucleus, cytoplasm, cell membrane, mitochondria and ribosomes. Plant and algal cells also have a cell wall, and often have chloroplasts and a permanent vacuole. Bacterial and yeast cells have different structures to animal and plant cells.
Dissolved substances pass into and out of cells by diffusion.

Question 3

Nucleus

Answer 3

the nucleus stores the cell’s hereditary material, or DNA, and it coordinates the cell’s activities

Question 4

Cytoplasm

Answer 4

the material or protoplasm within a living cell, excluding the nucleus, where reactions take place

Question 5

Cell membrane

Answer 5

It consists of a lipid bilayer with embedded proteins. The basic function of the cell membrane is to protect the cell from its surroundings. The cell membrane controls the movement of substances in and out of cells and organelles. In this way, it is selectively permeable to ions and organic molecules.

Question 6

Mitochondria

Answer 6

Mitochondria are known as the powerhouses of the cell. They are organelles that act like a digestive system which takes in nutrients, breaks them down, and creates energy rich molecules for the cell. The biochemical processes of the cell are known as cellular respiration.

Question 7

Ribosomes

Answer 7

a minute particle consisting of RNA and associated proteins found in large numbers in the cytoplasm of living cells. They bind messenger RNA and transfer RNA to synthesize polypeptides and proteins.

Question 8

Eukaryotic cells

Answer 8

An organism whose cells contain a nucleus surrounded by a membrane and whose DNA is bound together by proteins (histones) into chromosomes.

Question 9

Prokaryotic cells

Answer 9

The Prokaryotic Cell. Prokaryotes are unicellular organisms that lack organelles or other internal membrane-bound structures. Therefore, they do not have a nucleus, but, instead, generally have a single chromosome: a piece of circular, double-stranded DNA located in an area of the cell called the nucleoid

Question 10

Root hair cell

Answer 10

A root hair, or absorbent hair, the rhizoid of a vascular plant, is a tubular outgrowth of a trichoblast, a hair-forming cell on the epidermis of a plant root. As they are lateral extensions of a single cell and only rarely branched, they are invisible to the naked eye.

Question 11

Photosynthetic cells

Answer 11

In plants and algae, which developed much later, photosynthesis occurs in a specialized intracellular organelle—the chloroplast. Chloroplasts perform photosynthesis during the daylight hours. The immediate products of photosynthesis, NADPH and ATP, are used by the photosynthetic cells to produce many organic molecules.

Question 12

Phloem cells

Answer 12

A tissue in vascular plants that conducts food from the leaves and other photosynthetic tissues to other plant parts. Phloem consists of several different kinds of cells: sieve elements, parenchyma cells, sclereids, and fibers.

Question 13

Diffusion

Answer 13

Diffusion is the movement of a substance from a region of higher concentrationto a region of lower concentration. Diffusion is the movement of gas or solute molecules from a region of higher concentration to a region of lower concentration until they are equal.

Question 14

Concentration

Answer 14

The measure of the amount of a sub-component (especially solute) in a solution. (2) The ratio of the mass or volume of a substance (solute) to the mass or volume of the solvent or solution

Question 15

Dilute

Answer 15

Lessen the strength or flavor of a solution or mixture; cut bourbon.Reduced in strength or concentration or quality or purity; diluted alcohol; a dilute solution; dilute acetic acid.A substance with ‘watered down chemical properties by adding a chemical that can neutralise its effect

Question 16

Osmosis

Answer 16

a process by which molecules of a solvent tend to pass through a semipermeable membrane from a less concentrated solution into a more concentrated one

Question 17

Osmosis in animals

Answer 17

In animal cells. Osmosis explains how water moves in and out of animal cells through the cell membrane. … If water continues to enter a cell it will eventually burst. These things happen because animal cells are not surrounded by an inelastic cell wall, unlike plant cells.

Question 18

Tugor

Answer 18

Turgor pressure is the pressure of water pushing the plasma membrane against the cell wall of a plant cell. Find out about turgor pressure in biology with help from a science professional in this free video clip.

Question 19

Plasmolysis

Answer 19

Plasmolysis is the process in which cells lose water in a hypertonic solution. The reverse process, cytolysis, can occur if the cell is in a hypotonic solution resulting in a lower external osmotic pressure and a net flow of water into the cell.

Question 20

Active transport

Answer 20

Active transport is the process by which dissolved molecules move across a cell membrane from a lower to a higher concentration. In active transport, particles move against the concentration gradient - and therefore require an input of energy from the cell

Question 21

Adaptation

Answer 21

any alteration in the structure or function of an organism or any of its parts that results from natural selection and by which the organism becomes better fitted to survive and multiply in its environment.