sexta-feira, 21 de novembro de 2014

Vírus: seres vivos ou não?

Vírus: seres vivos ou não?

Sabemos que uma das características dos seres vivos é apresentar células constituindo seus corpos, além de outras, tais como, poir exemplo a nutrição e a reprodução, dentre outras.
Entretanto, ao analisarmos os vírus percebemos que eles apresentam funções vitais. Porém, não possuem células.

Os vírus são seres bem simples e extremamente pequenos, são tão pequenos que eles só podem ser  visualizados com o auxílio de microscópios eletrônicos.

Não possuem células, formados, principalmente, por proteínas e ácidos nucleicos. O ácido nucleico pode ser tanto DNA quanto RNA, alguns poucos vírus podem possuir os dois.

Os vírus, só realizam suas atividades vitais quando estão no interior de células vivas, por isso, são considerados parasitas intracelulares obrigatórios.

Vírus

                                                                      Ebóla


                                                                       Hepatite


                                                                  HPV


                                                                  Herpes



                                                               Caxumba



                                                                    HIV


                                                            Catapora



                                                          Rubéola






                                                      Febre Amarela






                                                 Bacteriófago


·         O bacteriófago é o vírus que parasita bactérias.



Quanto à reprodução, esta só ocorre no interior de uma célula hospedeira. Infectam a célula hospedeira ligando suas proteínas virais à proteína receptora desta, ocorre a multiplicação do material genético, surgem novos vírus.






Dentre as principais viroses, podemos destacar:
- Aids     - Catapora      - Caxumba    - Dengue     - Febre amarela   - Gripe
- Herpes       - HPV   - Poliomielite   - Raiva    - Rubéola     - Sarampo
- Varíola    -  Ebola  - Covid 19

sábado, 1 de novembro de 2014

Exercícios: zero e first conditional

                                                  Exercises

 A. Use the  Zero conditional and  make phrases:
Ex.: (not / rain / the flowers / die)
If it doesn’t rain, the flowers die

1. (not/I / wake up late / I / be late for work)
_____________________________________________

2. (not/my husband / cook / he / burn the food)
_____________________________________________

3. (not/Julie / not wear a hat / she / get sunstroke)
_____________________________________________

4. (not/children / not eat well / they / not be healthy)
_____________________________________________

5. (not/you / mix water and electricity / you / get a shock)
_____________________________________________

6. (not/people / eat / too many sweets / they / get fat)
_____________________________________________

7. (not/you / smoke / you / get yellow fingers)
_____________________________________________

8. (not/children / play outside / they / not get overweight)
_____________________________________________

9. (not/you / heat ice / it / melt)
____________________________________________

10. (not/I / speak to John / he / get annoyed)
____________________________________________

11. (I / feel good the next day / I / go to bed early)
_____________________________________________

12. (lots of people / come / Jenny / have a party)
_____________________________________________

13. (she / buy expensive clothes / she / go shopping)
_____________________________________________

14. (my daughter / pass her exams / she / work hard)
_____________________________________________

15. (David / be sick / he / drink milk)
_____________________________________________

16. (the river / freeze / it / be very cold)
_____________________________________________

17. (I / like to visit the museums / I / be in a new city)

_____________________________________________

18. (I / cycle to work / the weather / be fine)
_____________________________________________

19. (my flatmate / clean it really well / she / clean the house)
_____________________________________________

20. (everybody / be grumpy / it / rain a lot)
_____________________________________________



B.    Complete the zero conditional sentences with the verb in brackets. Use contractions where possible.

1. If you press that button, the light­­­­­­­­____________________(come) on.

2.It's easier to sleep if____________________________(you / not / be) stressed.score

3.The teacher gets angry if __________________(we / not / work) hard.

4.If___________________(I / go) on a boat, I always feel sick.score

5.They play football if­­­­­­­­­­__________________________(they / not / have) any homework.score

6.If you freeze water,_________________________( it / turn) to ice.

7. His mother gets annoyed if _____________(he / be) late.

8. If_________________________ (I / not / know) a word, I look in my dictionary.

9. If people __________(eat) too much, they ___________(get) fat.

10. If you _________________(touch) a fire, you ______________( get) burned.

11.People _____________( die) if they________________ (not eat).

12.You______________( get)  water if  you ___________(mix) hydrogen and oxygen.

13. Snakes ___________( bite) if they ________(be) scared

14.If babies__________( be) hungry, they__________( cry)


            C.   Make phrases using the zer or first conditional              

1)      If I  ______________(go) out tonight, I ____________ (go) to the cinema.


2)      If you  _________(get) back late, I ________ (be) angry.

3)      If we ______________ (not/see) each other tomorrow, we  ____________(see) each other next week.

4)       If he ___________ (come) , I___________  (be) surprised.

5)       If we  _________(wait) here, we ___________ (be) late.

6)      If we  ___________(go) on holiday this summer, we _______________ (go) to Spain.

7)       If the weather  _________________________(not/improve) , we  __________(not/have) a picnic.

8)      They  _____________(go) to the party if they  __________(be) invited.

9)      If I______________  (not/go) to bed early, I  ____________(be) tired tomorrow.

          10) If we ___________ (eat) all this cake, we ____________  (feel) sick .

          11) She _________ (stay) in London if she________  (get) a job.

         12) If you ________________ (not/want) to go out, I _____________ (cook) dinner at home.

         13) I  ____________(come) early, if you _________ (want).

        14) He ______________ (not/get) a better job if he  ________________(not/pass) that exam.

        15) I_____________  (buy) a new dress if I  __________ (have) enough money.

    16) She  ______________(cook) dinner if you  ______________________(go) to the supermarket.

    17) They________________  (go) on holiday if they  ___________(have) time.

      18) We  _______(be) late if we _______________ (not/hurry).

      19) She ___________ (take) a taxi if it  ______(rain).

      20) I ____________ (not/go) if you _____________ (not/come) with me.

      21) I ___________(sell) you any alcohol, unless you ________________(be)over 18.

      22) If it's true, we ___________(be) fired.

      23) I won't go to the party unless she ______________(invite) me.

      24) If you take an aspirin, you ____________ better. (feel)

      25) Unless the weather _________  (get) better, I ________________ ( arrive)

      26) Unless she _______________(improve) her results, she ____________(not/go)to the concert.

       27) If this is a good article, I_________(be) Formula One driver!

      28) If you heat water to 100 C, it_______(boil)

      29) I______________(be) grateful if you _________(keep) what I said to yourself.

      30) If you want to be with me,____________(tell) me that you love me.

      31) If I have to do this, I ____________(be)

     32) I_________(be) very upset if those gossips __________________(turn out) to be true.

    33) If world is a stage, then life _________(be) a game.