Question

 What do pollen grains contain? What is pollination? What are advantages of pollen?

 What are the evolutionary advantages of seeds over spores?

 What are the two key traits of angiosperms?

 Describe the four types of floral organs.

 What are the five key traits of nearly all plants? 1) Alternation of generations; 2) Multicellular, dependent

 embryos); 3) Walled spores produced in sporangia; 4) Multicellular gametangia: 5) Apical meristems. Plants also have cuticle, a waxy covering of the epidermis; stomata, openings controlled by guard cells that allow for gas exchange between the outside air and the plant; and mycorrhizae, symbiotic associations between fungi and land plants.

 What does a fruit develop from? What are the two main

 types of fruits? What is the function of fruits? What are

 the various fruit adaptations that enhance the survival of fruits and the seeds contained within them?

 What are the features of animal-pollinated flowers that make these flowers attractive to animal pollinators? Characteristics of a flower often correlate with its

 pollinator. These correlations are called pollination syndromes, and these include: Scent, flower shape,

 and flower color.

 Plants are autotrophs that sustain themselves, do not usually consume organic molecules derived from other

 organisms, and through the process of photosynthesis, convert CO2 and H2O to sugars and other organic

 molecules.

 Define: photoautotrophs, chemoautotrophs, and chemoheterotrophs (heterotrophs).

 What is chlorophyll? What is the function of chlorophyll? What is mesophyll?

 What is the function of stomata?

Answer 1

• Pollen grains contain nutrients ( protein 7-26%; carbohydrate 24-48%; fats 0.9-14.5%). They are taken as tablets or syrups to improve health, enhance performance of athletes and race horses. Beside these, it also contains the tube cell, which will eventually become the pollen tube, and a generative cell, which contains the male sperm nuclei needed for fertilization.
• The transfer of pollen grains from the anther to the stigma is called pollination. Pollinating agents are animals such as insects, birds, and bats; water; wind; and even plants themselves.
• Advantages of pollen : pollination is of two types

1) self pollination. 2) cross pollination.

Advantages of self pollination: a) it maintains the parental characters.

b) It is used to maintain pure lines for hybridization experiments

c) It also eliminates some bad Recessive characters.

d) Plants do not need to produce large number of pollen grains and devices for attracting insect pollinators.

Advantages of cross pollination: a) It introduces genetic recombination and hence variations.

b) Increases adaptability of the offspring towards changes in the environment

c) Plants produce are more resistant to diseases.

• Seeds and spores are modes of reproduction found in plants, fungi and some bacteria. Not all plants produce seeds as a means of reproduction. Non-flowering plants, such as ferns, reproduce through the use of spores. While both seeds and spores produce the next generation, seeds are a more developed way of reproduction that offers many advantages:

1. Seed coat: The spore has no outer protection. A seed is a multicelled organism with an outer shell that protects the inside from damage, dessication and other adverse conditions.
2. Nourishment: Each seed contains nourishment for the embryo inside the seed via endosperm. The spore, being a single-celled organism, does not have any built-in system to help a new plant or fungus begin the growth process.
3. Fully developed embryo: Inside each seed is a fully developed embryo that is ready to begin growing. Having an embryo already grown gives a seed plant a better chance at survival as opposed to a spore.

4. No Water Required : Seeds do not necessarily need water to germinate and grow, although some require water to soften the seed coat. However, all spores require water before the spore begins its growing process.

• Two key traits of angiosperms are:

1. All angiosperms have flowers at some stage in their life. The flowers serve as the reproductive organs for the plant, providing them a means of exchanging genetic information.

2. Another key trait for angiosperms is the production of endosperm. Endosperm is a material that forms after fertilization and serves as a highly nutritional food source for the developing seed and seedling.

• Four types of floral organs are :

1. Calyx: the sepals collectively are called as calyx. They are usually green in colour and protect the inner whorls of flower especially during bud formation.

2. Corolla: it consists of coloured petals. They are normally large often frgrant and bright coloured. Their primary function is to attract animals and insects for pollination.

These two were accessory parts while rest two are reproductive parts.

3. Androecium: also known as stamen. It is the male reproductive organ. It is differentiated into filament, anther and connective.

4. Gynoecium: also known as carpel. It is the female reproductive organ. It is differentiated into: ovary, style and stigma.